Vitamin A, vitamin D, vitamin E and vitamin K are all fat soluble but B Vitamin complex as well as vitamin C aren’t, being water soluble instead. These water soluble vitamins are regularly eliminated from your body through excretory products such as urine while the fat soluble vitamins will remain stored in your body. Because of this, you must take water soluble vitamins regularly. In order to have proper digestion and absorption as well as a continuous vitamin flow, doctors recommend you split up your vitamins when taking them.